Not that we necessarily want to encourage any authors to use these, but they are certainly fun to know about:
14 Punctuation Marks That You Never Knew Existed
(Go to that article to see the actual marks and get a full explanation.)
A few are really cool--I actually want to see a story submission using these! (Of course, first you have to figure out how to get the weird characters to show in your Word file. Try checking http://
Exclamation Comma (when you want to indicate excitement, but not end the sentence yet)
Question Comma (when asking a question but continuing the sentence)
Interrobang (the punctuation equivalent of OMGWTF?!)
Snark (to indicate the sentence has a sarcastic or ironic meaning) [Actually, I'm wondering if the article author made this one up!]
Of course, the problem is that readers (or 99.9% fo them) won't know what these marks are or what they mean. They'd likely just think it's a misprint or typo, alas.
Many of the rest of the listed marks are primarily used by copy editors and proofreaders to indicate changes or text formatting, they are not something you'd see in published story/book text. And there are a few with specialized technical usages.